[RC5] Reduce, Reuse, Recycle

Jeff Lawson jlawson at bovine.net
Thu Dec 30 18:46:22 EST 1999

Hash: SHA1

As many people may be aware, we are rapidly completing more and more
of the CSC keyspace every day and this means that it will become more
and more important for everyone to ensure that their clients are only
processing "fresh" work units.  You should try to ensure that all of
your clients and personal proxies are configured so that they buffer
blocks to last them a period no longer than about 5 days (and
preferably no shorter than 24 hours).  If you take these measures,
you will not run into a high possibility of allowing your machines to
process blocks that have been already reassigned to someone else.

I would also like to emphasize the importance of not intentionally
deleting/discarding "fresh" blocks, if possible.  Blocks that were
fetched more than 5 days ago are "stale" and can be safely discarded
(but they can still be processed, though with a possibility that it
may be duplicated work).  However, discarding or wasting blocks that
are still fresh only contributes to the need to recycle more
frequently, since we run out of undistributed blocks more quickly.

We would also like to recommend that everyone verify that they are
running the most recent versions of the client for their platform, if
possible.  Improvements in the recent versions of the x86 and MacOS
clients have resulted in very dramatic speed increases in CSC
processing speed.  If you are not running one of these recent
clients, you might not be contributing as much as you could

If you have not yet even upgraded your machines to a CSC-capable
client and are still only running RC5-64, it is not too late to
upgrade!  Also if you helped us beta test our pre-release CSC
clients, be sure that you are now at least running final-release
versions of the clients.  Some of the beta clients did not have
built-in expiration dates and we are still getting a lot of blocks
being processed by these buggy versions.  Because of the blocks
reported by these pre-release versions, and also our experimental
distribution of redundant blocks for operational verification, the
actual percentage of valid unique blocks we have checks is actually a
little bit less than the percentage reported on statsbox and on the
main webpage.

With those things said, we will initiate a CSC keyspace recycle as of
0300 UTC tonight.

On a related note, a couple of weeks ago we began the first major
attempts to begin recycling old RC5-64 subspaces.  Work units for
which completion notifications had not been received have begun to be
reissued.  However, there is probably no significant need to worry
about reprocessing blocks that are still actively being processed
since the subspaces that are we have begun redistributing were
originally distributed from October 1997.

Version: PGPfreeware 6.5.2 for non-commercial use <http://www.pgp.com>


Jeff Lawson   http://www.bovine.net/   http://www.cs.hmc.edu/~jlawson/
Jeffrey_Lawson at alumni.hmc.edu  jlawson at bovine.net  bovine at distributed.net
Programmer, Developer, Mascot, Founder of the largest computer on earth!
Don't waste those cycles!  Put them to use!  http://www.distributed.net/

To unsubscribe, send 'unsubscribe rc5' to majordomo at lists.distributed.net
rc5-digest subscribers replace rc5 with rc5-digest

More information about the rc5 mailing list